Multifunctional protein that functions as a downstream effector of RALA and RALB (PubMed:7673236). As a GTPase-activating protein/GAP can inactivate CDC42 and RAC1 by stimulating their GTPase activity (PubMed:7673236). As part of the Ral signaling pathway, may also regulate ligand-dependent EGF and insulin receptors-mediated endocytosis (PubMed:10910768, PubMed:12775724). During mitosis, may act as a scaffold protein in the phosphorylation of EPSIN/EPN1 by the mitotic kinase cyclin B-CDK1, preventing endocytosis during that phase of the cell cycle (PubMed:12775724). During mitosis, also controls mitochondrial fission as an effector of RALA (PubMed:21822277). Recruited to mitochondrion by RALA, acts as a scaffold to foster the mitotic kinase cyclin B-CDK1-mediated phosphorylation and activation of DNM1L (PubMed:21822277). {ECO:0000269|PubMed:10910768, ECO:0000269|PubMed:12775724, ECO:0000269|PubMed:21822277, ECO:0000269|PubMed:7673236}. Could also function as a primary ATP-dependent active transporter for glutathione conjugates of electrophiles. May also actively catalyze the efflux of a wide range of substrates including xenobiotics like doxorubicin (DOX) contributing to cell multidrug resistance. {ECO:0000269|PubMed:10924126, ECO:0000269|PubMed:11300797, ECO:0000269|PubMed:11437348, ECO:0000269|PubMed:9548755}. This is the function of RALBP1 (ralA binding protein 1, ENSG00000017797).